The class of polymers of carbon monoxide and olefin(s) has been known for a number of years. Brubaker, U.S. Pat. No. 2,495,286, produced such polymers of relatively low carbon monoxide content in the presence of free radical initiators, e.g., peroxy compounds. U.K. 1,081,304 produced similar polymers of higher carbon monoxide content in the presence of alkylphosphine complexes of palladium salts as catalyst. Nozaki extended the reaction to produce linear alternating polymers in the presence of arylphosphine complexes of palladium moieties and certain inert solvents. See, for example, U.S. Pat. No. 3,694,412.
More recently, the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon has become of greater interest in part because of the greater availability of the polymers. The more recent processes for the production of the linear alternating polymers, now becoming known as polyketones or polyketone polymers, are illustrated by a number of published European Patent Applications including 121,965, 181,014, 213,671 and 257,663. The process typically involves the use of a catalyst composition formed from a compound of palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic or antimony.
The resulting materials are relatively high molecular weight thermoplastic polymers having established utility as premium thermoplastics in the production of shaped articles such as containers for food and drink by procedures which are conventionally employed with thermoplastics. Although the linear alternating polymers are crystalline with well defined melting points, the polymers do tend to lose crystallinity to some extent when exposed to multiple melting/solidification cycles. This apparent loss of crystallinity results in decreases of certain of the desirable properties of the polymers. Stabilization against undue loss of crystallinity of the polyketone polymers in the presence of aluminum stearate is shown by copending U.S. patent application Ser. No. 358,218, filed May 30, 1989 U.S. Pat. No. 4,954,555. Similar stability in the presence of aluminum phenoxide is shown by copending U.S. patent application Ser. No. 351,369, filed May 15, 1989 U.S. Pat. No. 4,950,703. The presence of aluminum hydrogels in polyketone polymers is shown by copending U.S. patent application Ser. No. 338,011, filed Apr. 14, 1989. It would be of advantage to provide other compositions of the linear alternating polymers which have been stabilized against loss of crystallinity upon melting/solidification cycles. Expressed differently, it would be of advantage to provide compositions of the linear alternating polymers which exhibit improved melt stability.